Reflector for cinematographic purposes



Oct-1, 1935. MORENO REFLECTOR FOR CINEMATOGRAPHIC PURPOSES Filed April25, 1934 Patented Oct. 1, 1935 UNITED STATES PATENT. OFFICE REFLECTORFOR CINEMATOGRAPHIC PURPOSES ration of Delaware Application April 25,1934, Serial No. 722,271

3 Claims.

This invention relates to an improved form of reflector particularlyadapted for projection of two or more frames of motion picture filmsimultaneously. I

During projection of motion picture film it is highly desirable that theentire picture area. of the frame being projected be uniformly andintensely illuminated. In the projection of isomorphous images bearingrecords of different color value, as is the case in the projection ofcolored pictures by the additive method, it is diflicult to illuminateboth of the frames with suflicient intensity when the normal lightsource is employed.

This invention permits the use of a conventional reflector such as anare or tungsten-filament but contemplates a modification of thereflecting surface itself in such manner that the double gate employedis fully illuminated.

It has been discovered that when the usual concave reflector (eitherspherical or parabolic) is bisected by a plane passing through the axisof the reflecting surface, such plane preferably also passing throughthe line of demarcation between adjoining frames which it is desired tosimultaneously project, then the two sectors thus formed may be pivotedon axes or axis parallel to such line of demarcation and permit a singlelight source, such as the. are or tungsten filament, to uniformly andintensely illuminate both frames of the picture being projected.

In order to fully describe the invention, reference will be had to theappended drawing, in which:

Fig. 1 diagrammatically represents a conventional reflector.

Fig. 2 represents the illumination obtainable with such reflector.

Fig. 3 diagrammatically represents one form which my improved form ofreflector may assume.

Fig. 4 represents the distribution of illumination obtainable by myimproved reflector.

As shown in the drawing, the film gate, indicated at l0, contains twoapertures II and I2 separated by a horizontal dividing member wherebytwo adjacent picture areas on the film l3 may be simultaneouslyilluminated and projected. A carbon arc reflector is used for purposesof illustration and may include a spherical reflector M- suitablymounted in the rear of the are l5 (or other light source). Means formoving the reflector l4 toward and away from the crater of the are orfor pivoting the reflector l4 so as to throw the beam directly againstthe gate, are

customarily provided but such means are not shown in the drawing as theyare well known in the art.

As shown in Fig. 2, the circle of light thrown by the reflector I4 isindicated by the dotted lines I6. As the conventional reflector isdesigned to intensely illuminate but a. single frame or single aperture,the two gates II and I2 are not uniformly illuminated. If an attempt ismade to enlarge the circle I6 by moving the 10 reflector l4 closer tothe are or light source l5 so as to form the enlarged circle H, theeffective light intensity on the area of the film gates H and I2 ismaterially diminished and a large proportion of the light is wasted,being directed 15 upon the gate itself and not upon the gate apertures.

In accordance with my invention, the spherical or parabolic reflectingsurface It is split horizontally by a. plane passing through the axis of20 the reflector so as to form concave reflecting sectors 20 and 2|.These reflecting sectors may be hinged together as indicated at 22 andmeans for adjustably positioning the sectors relatively to each othermay be provided such as the shafts 25 23 and 24 threaded throughstationary supports 25 and 26 respectively, the ends of the shafts beingrevolvabiy connected to the sectors 20 and 2| respectively so that byoperation of the thumb screws 21 and 28 carried by the outer ends of theshafts, the sectors 20 and 2| may be positioned relatively to oneanother.

In this manner, the conjugate points of the reflecting members 20 and 2|may be shifted relatively to one another in a vertical plane. As aresult, the improved reflector may be caused to illuminate the twoadjacent film gates II and |2 in the manner illustrated in Fig. 4,wherein the upper reflector 20 produces a ring of illumination,indicated at 30,' whereas the lower reflector sector 2| produces thering of illumination 3|. The same light source I5 is thus caused toilluminate adjacent film gates much more uniformly and economically thanis the case with a normal reflector.

I claim: I

l. A reflector particularly adapted to the projection of two adjacentframesof motion picture film simultaneously, comprising a pair ofcomplementary concave reflector surfaces pivoted on a. horizontal axiswhereby the focal points thereof may be caused to coincide or to bespaced vertically a desired distance.

2. A reflector particularly adapted to the projection of two adjacentframes of motion picture film simultaneously, comprising a pair ofcomplementary concave reflector surfaces provided with adjacentdlametrical edges, and means for pivoting said complementary reflectorsurfaces independently along axes parallel to said edges.

3. In a reflector system particularly adapted to the projection of aplurality of longitudinally disposed and adjacent frames of motionpicture 10 film simultaneously, comprising a single light source, a pairof complementary concave reflector surfaces provided with adjacentdiametrical edges in operative relation to said light source, and meansfor pivoting said complementary reflector surfaces independently alongaxes parallel to said edges whereby the converging beams reflected bysaid reflector surfaces may be adjustably positioned vertically.

GABRIEL GARCIA MORENO.

